1. Field of the Invention
The present invention relates to memory devices and systems including error correction code (ECC) logic.
2. Description of Related Art
Memory technologies used for integrated circuit memories are being developed at smaller and smaller technology nodes, and are being deployed on larger and larger memory arrays on a single integrated circuit. As the technology for memory cells advances, the margins for sensing the data can become tighter. Also, the ability of the memory cells to hold data values in the presence of disturbance of the memory cell state caused by high speed and high volume accesses to the memory cells and to neighboring memory cells can be limited by the tighter margins.
To address issues like those that arise from tighter margins and memory cell disturbance, as these technologies scale in size and density, use of error correcting codes (ECCs) embedded with integrated circuit memory has become more widespread. In addition to correcting erroneous memory bits in a memory device, ECC information that may be produced in the process of correcting may be used for memory management functions. The memory management functions may include bad block management, re-mapping, refreshing, and wear leveling.
For example, a memory controller may base its decision on whether to refresh a certain page in the memory device on the ECC information for the page. However, when the ECC logic that corrects erroneous memory bits is embedded in the integrated circuit memory, the ECC information is not easily available to the memory controller that is external to the integrated circuit memory. ECC corrected data alone does not include the ECC information, such as which bits have been corrected or how many bits have been corrected. So, in an environment in which only ECC corrected data is provided to the memory controller, information needed about the use of the ECC codes that can be used in memory management functions may not be available.
It is desirable to provide a solution for providing the ECC information to a memory controller external to the integrated circuit memory, such that the memory controller can perform memory management functions with necessary ECC information.